From nobody Fri Dec 19 19:55:41 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D7F752980DD for ; Fri, 11 Apr 2025 05:42:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744350136; cv=none; b=REo8vJyJWSS9tgQEQEzZLmZq4qo3WR6l3fFf9dLtdkPubRJToX2krDlKyCR5hQyc7LDq9YR7ZV7LzUPN3Ey2bHbPspx9cC5SGv0AVUa2Nzp3Lc4TvdI5a9GW3N9xpP/gEAgWTJ3EwDNbFkdVKabI8yLKkhS3lc1yQIwzWqMTZSE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744350136; c=relaxed/simple; bh=62aMsQYVHPp7bHeNS3D+Wg81XfB0kzlWGa83pIbg3qY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZldHYrFqiJt8F/odS7q7HmRgMzePE/CIP0i/hecF387ZFN1d4ak/ehqgzSWaJ6kOVTcSI2Y6LiTujFJMeSlie0e/Hg4ybKBZQ5KTAc053tpY2/DXJaGagMUCe/WQe5N/bV6/hWttwcAmXAymtKLSmJEed5zeTnVM9Bsmzs1fdSI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ru8tlPD5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ru8tlPD5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8554C4CEE2; Fri, 11 Apr 2025 05:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744350136; bh=62aMsQYVHPp7bHeNS3D+Wg81XfB0kzlWGa83pIbg3qY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ru8tlPD5fg0IQEnUrNUe4fNZcRl4dg5cK1AvS0ebO96jH8SFPUl86JMxG418yUWFc Tjz1fXst2hM0hJNBWXi4cEa/4pL2BdJqrZBKEl0GUQtQ+w0/VCgziwMkA3ccT4O8a3 EX8IXb9CiQv/QCKv0qZfnxlHkGciLdusq+v/mN1qObbcKczs193DawsV9LpLaKdHaf d3AT3ke+ywRNrkH0+FMgaQzaHt7h/ntABUumc9CQ3HrmCwstT70u/lJ+BPlFtLpUXA 7tVzYDhT2eboJjc/1DNZLnCMmLwFeJgw8NIKlgBcL7gy0+ZFJaH6GmDF/+mgrsDcRh HNKHN8rwsAfhw== From: Ingo Molnar To: linux-kernel@vger.kernel.org Cc: Juergen Gross , "H . Peter Anvin" , Linus Torvalds , Peter Zijlstra , Borislav Petkov , Thomas Gleixner , Ingo Molnar Subject: [PATCH 27/53] x86/alternatives: Introduce 'struct smp_text_poke_array' and move tp_vec and tp_vec_nr to it Date: Fri, 11 Apr 2025 07:40:39 +0200 Message-ID: <20250411054105.2341982-28-mingo@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20250411054105.2341982-1-mingo@kernel.org> References: <20250411054105.2341982-1-mingo@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" struct text_poke_array is an equivalent structure to these global variables: static struct smp_text_poke_loc tp_vec[TP_VEC_MAX]; static int tp_vec_nr; Note that we intentionally mirror much of the naming of 'struct text_poke_int3_vec', which will further highlight the unecessary layering going on in this code, and will ease its removal. No change in functionality. Signed-off-by: Ingo Molnar --- arch/x86/kernel/alternative.c | 43 +++++++++++++++++++++++----------------= ---- 1 file changed, 23 insertions(+), 20 deletions(-) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index ee6ff7660563..d1647aa46db5 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -2467,14 +2467,21 @@ struct smp_text_poke_loc { }; =20 struct text_poke_int3_vec { - struct smp_text_poke_loc *vec; int nr_entries; + struct smp_text_poke_loc *vec; }; =20 static DEFINE_PER_CPU(atomic_t, int3_refs); =20 static struct text_poke_int3_vec int3_vec; =20 +#define TP_ARRAY_NR_ENTRIES_MAX (PAGE_SIZE / sizeof(struct smp_text_poke_l= oc)) + +static struct smp_text_poke_array { + int nr_entries; + struct smp_text_poke_loc vec[TP_ARRAY_NR_ENTRIES_MAX]; +} text_poke_array; + static __always_inline struct text_poke_int3_vec *try_get_desc(void) { @@ -2510,10 +2517,6 @@ static __always_inline int patch_cmp(const void *key= , const void *elt) return 0; } =20 -#define TP_VEC_MAX (PAGE_SIZE / sizeof(struct smp_text_poke_loc)) -static struct smp_text_poke_loc tp_vec[TP_VEC_MAX]; -static int tp_vec_nr; - noinstr int smp_text_poke_int3_handler(struct pt_regs *regs) { struct text_poke_int3_vec *desc; @@ -2538,7 +2541,7 @@ noinstr int smp_text_poke_int3_handler(struct pt_regs= *regs) if (!desc) return 0; =20 - WARN_ON_ONCE(desc->vec !=3D tp_vec); + WARN_ON_ONCE(desc->vec !=3D text_poke_array.vec); =20 /* * Discount the INT3. See smp_text_poke_batch_process(). @@ -2627,8 +2630,8 @@ static void smp_text_poke_batch_process(struct smp_te= xt_poke_loc *tp, unsigned i =20 lockdep_assert_held(&text_mutex); =20 - WARN_ON_ONCE(tp !=3D tp_vec); - WARN_ON_ONCE(nr_entries !=3D tp_vec_nr); + WARN_ON_ONCE(tp !=3D text_poke_array.vec); + WARN_ON_ONCE(nr_entries !=3D text_poke_array.nr_entries); =20 int3_vec.vec =3D tp; int3_vec.nr_entries =3D nr_entries; @@ -2843,7 +2846,7 @@ static void text_poke_int3_loc_init(struct smp_text_p= oke_loc *tp, void *addr, } =20 /* - * We hard rely on the tp_vec being ordered; ensure this is so by flushing + * We hard rely on the text_poke_array.vec being ordered; ensure this is s= o by flushing * early if needed. */ static bool text_poke_addr_ordered(void *addr) @@ -2852,7 +2855,7 @@ static bool text_poke_addr_ordered(void *addr) =20 WARN_ON_ONCE(!addr); =20 - if (!tp_vec_nr) + if (!text_poke_array.nr_entries) return true; =20 /* @@ -2861,7 +2864,7 @@ static bool text_poke_addr_ordered(void *addr) * is violated and we must first flush all pending patching * requests: */ - tp =3D &tp_vec[tp_vec_nr-1]; + tp =3D &text_poke_array.vec[text_poke_array.nr_entries-1]; if ((unsigned long)text_poke_addr(tp) > (unsigned long)addr) return false; =20 @@ -2870,9 +2873,9 @@ static bool text_poke_addr_ordered(void *addr) =20 void smp_text_poke_batch_finish(void) { - if (tp_vec_nr) { - smp_text_poke_batch_process(tp_vec, tp_vec_nr); - tp_vec_nr =3D 0; + if (text_poke_array.nr_entries) { + smp_text_poke_batch_process(text_poke_array.vec, text_poke_array.nr_entr= ies); + text_poke_array.nr_entries =3D 0; } } =20 @@ -2880,9 +2883,9 @@ static void smp_text_poke_batch_flush(void *addr) { lockdep_assert_held(&text_mutex); =20 - if (tp_vec_nr =3D=3D TP_VEC_MAX || !text_poke_addr_ordered(addr)) { - smp_text_poke_batch_process(tp_vec, tp_vec_nr); - tp_vec_nr =3D 0; + if (text_poke_array.nr_entries =3D=3D TP_ARRAY_NR_ENTRIES_MAX || !text_po= ke_addr_ordered(addr)) { + smp_text_poke_batch_process(text_poke_array.vec, text_poke_array.nr_entr= ies); + text_poke_array.nr_entries =3D 0; } } =20 @@ -2892,7 +2895,7 @@ void __ref smp_text_poke_batch_add(void *addr, const = void *opcode, size_t len, c =20 smp_text_poke_batch_flush(addr); =20 - tp =3D &tp_vec[tp_vec_nr++]; + tp =3D &text_poke_array.vec[text_poke_array.nr_entries++]; text_poke_int3_loc_init(tp, addr, opcode, len, emulate); } =20 @@ -2912,9 +2915,9 @@ void __ref smp_text_poke_single(void *addr, const voi= d *opcode, size_t len, cons struct smp_text_poke_loc *tp; =20 /* Batch-patching should not be mixed with single-patching: */ - WARN_ON_ONCE(tp_vec_nr !=3D 0); + WARN_ON_ONCE(text_poke_array.nr_entries !=3D 0); =20 - tp =3D &tp_vec[tp_vec_nr++]; + tp =3D &text_poke_array.vec[text_poke_array.nr_entries++]; text_poke_int3_loc_init(tp, addr, opcode, len, emulate); =20 smp_text_poke_batch_finish(); --=20 2.45.2